The saga of the Severn Barrage is typical of our inability to plan for the
future, argues Philip Johnston.

Why are we so useless at strategy? This may seem like an odd question to pose 24 hours after the Government has published its National Security Strategy, and on the day it unveils its Strategic Defence and Security Review. George Osborne's Comprehensive Spending Review, to be announced tomorrow, has, one hopes, been guided by a strategic approach. Surely that's enough strategy to be going on with.

Except we know, don't we, that simply putting the word "strategic" into a statement is meaningless if nothing is actually done to prepare for the eventualities identified by the thinking. A report yesterday from the Commons public administration select committee gave a pessimistic assessment of Britain's aptitude in this area: "We have all but lost the capacity to think strategically," it said. "We have simply fallen out of the habit, and have lost the culture of strategy making."

The committee was thinking less about day-to-day planning than about what we once called Grand Strategy. This is something we used to be good at, especially in the imperial era that we are no longer allowed to talk about. As recently as the late 1950s, Harold Macmillan's government produced a Study on Future Policy to assess where Britain would be by 1970 on the basis of current policies. The end of the Cold War reduced the incentive to devise a new Grand Strategy in a similar vein. Yet we seek to remain a big player on the world stage, while at the same time cutting the means that allow us to observe that role.

It is a mistake, however, to see this purely in the context of foreign policy. What about strategic decision-making closer to home? Take the Severn Barrage, an engineering project to harness the tidal energy of Britain's longest river and produce enough electricity to power all of Wales. It was proposed as a renewable energy source in 1925 – long before there was any talk of global warming – because the Severn has the biggest tidal range in the world, apart from the Bay of Fundy in Canada. But the idea was shelved because of the then cost: £25 million. It was reconsidered in 1971, but again was thought to be too expensive (£500 million by that point) and, anyway, North Sea oil and gas were coming on stream so why waste money on an unnecessary tidal scheme? (We know the answer to that question now the North Sea bonanza has ended.)

The barrage idea was resurrected after the oil price shocks of the mid-1970s demonstrated the vulnerability of our economy to war in the Middle East, and the emergence of Opec as a supply cartel. Further thought was given following the Iranian revolution of 1979 and various proposals have been put forward since, though for some reason the cost is now estimated at around £15 billion. Yesterday, 85 years after the barrage was first proposed, the plug was finally pulled by Chris Huhne, the Energy Secretary, as he gave the go-ahead to eight new nuclear power stations that should have been ordered in the late 1990s.

Where is the strategic thinking here – or more pertinently, where was it two decades ago when it was needed? In the medium to long term, there is a potentially calamitous threat to the country's energy security. The Labour government's dithering over nuclear power has ensured the new reactors will not come on stream until 2018. We are increasingly dependent upon sources of oil and gas which are either to be found in areas whose stability cannot be guaranteed or whose main suppliers, like Russia, can turn the tap on and off to suit their political purposes.

Britain's economic security requires a steady and plentiful supply of energy, yet we are growing more reliant on gas supplies from Qatar. These are delivered in liquefied form by ship, yet we are planning to cut back the Royal Navy, which will be needed to protect the gas. Does this make sense? Moreover, conservationists say that wind power is a better renewable option than tidal power; but the former is expensive and arguably more destructive of the environment than the barrage would have been. In any case, tidal energy is guaranteed unless the Earth stops turning; wind isn't. Not much strategic thinking there.

We have become systemically bad at forward planning. Just look at the looming fiasco caused by Labour's immigration policy – a big increase in the population is imposing pressures on public services, notably schools, that simply weren't planned for. It has also been apparent for decades that a rapidly growing population of elderly people would put new pressures on the provision of care, the NHS and pensions. Yet how much planning has gone into coping with the consequences? The same is true about welfare policy, which has gone unreformed, pushing the costs of benefits up to unsustainable levels and creating an unemployed, poorly educated underclass subsidised by the taxpayer.

The Commons select committee said this tendency to "muddle through" was damaging the country's interests and urged the Government to devise a National Strategy. William Hague told its members that there needed to be "some sense of what we are trying to achieve as a country over a longer period". Longer than five years, we must hope.